Bacteria are very advanced forms of life.
I think self propagation is the demarcation.
A book called Of Molecules and Men by Francis Crick greatly shaped my thinking on this many years ago.
But self replication of organic molecules can happen at levels far too simple to be classified as "life".
My reference here is the above mentioned book by Addy Pross, "What is Life". She reviews more recent work... I'm on my second reading, hoping to "get" more of it.
Sorry about my previous response -- posting from a "smart-phone" can be quite problematic... ;-(
Here is a great book for updating your thinking:
Addy Pross: "What is Life? How chemistry becomes biology"